Chemicals play an important role int he quality of life in the modern world, and industrial laboratories are continuously developing new chemical formulations for a myriad of applications. It is important to characterize the inherent toxicity of new chemicals so that agents harmful to the populace can be identified. This research program is designed to both enhance the predictive power and reliability of chemical toxicity assays, and to reduce the number of animals required for testing. Many years of research strongly suggest that high-speed flow cytometry (FCM) is a technology which can significantly improve toxicity tests. With FCM, cells are moved at high speeds through a focused laser beam. Cell associated signals corresponding to particle size and fluorescent signals are stored to computer file for later analysis. Modern flow cytometers are capable of analyzing cells at extremely high rates (10,000 cells/sec). Once biological, chemical and FCM parameters are optimized, FCM technology is able to provide the following scoring characteristics: objectivity, efficiency, high throughput, and unprecedented accuracy. Advanced technologies such as FCM therefore have a great potential to significantly improve toxicity assays by permitting more expeditious and reliable analyses of biological responses to chemical exposure. The major research objectives of this application specifically relate tot he automation of three important mammalian toxicity endpoints: chromosome damaging effects, tumor promotion, and gene mutation. The experiments proposed for Phase II are intended to further develop and validate these automated test systems, and establish Litron Laboratories as an expert testing facility which is capable of providing industry and government with highly reliable FCM-based toxicity tests. A significant market exists for a facility which can supply such automated and improved assays. PROPOSED COMMERCIAL APPLICATION: ...New methods are needed to advance toxicology testing which can reduce the use of animals and moderate testing costs. ...Flow cytometry provides technology that expedites testing by objectively analyzing cell populations at high speeds. ...The commercial application of the technology is for reaching to industries that develop chemicals and pharmaceuticals where testing is required prior to broad distribution.